Braking device for a shuttle in a weaving machine

ABSTRACT

The braking device uses a one-piece plastics braking shoe to brake a shuttle. The shoe includes a braking part to engage the shuttle and guide shoes to guide the shuttle under the braking part. The shoe can include integral holding plates for securing the shoe to a reciprocating brake member or can cooperate with separable holding plates of metal for the same purpose.

0 Muted States Patent 1 91 1111 3,865,150

Demuth 1 Feb. 11, 11975 [54] BRAKING DEVICE FOR A SHUTTLE IN A 2,538,798l/l951 Pfarrwaller 139/125 2,693,830 11/1954 Darash 139/126 WEAVINGMACHINE I 2,713,357 7/1955 Peterson 139/186 [75] lnventor: Plans Demuth.Wmterthur. 3,014,505 12/1961 Herard et a1 139/126 Switzerland 3,124,1663/1964 Pfarrwaller 139/185 X [73] Assignee: Sulzer Brothers Ltd.,Winterthur,

Switzerland Primary Examiner-James Kee Chi Attorney, Agent, orFirm-Keny0n & Kenyon Reilly [22] Flled. June 4, 1973 Carr & Chapin [21]App]. No.: 366,523

[30] Foreign Application Priority Data [57] ABSTRACT June 20, 1972Switzerland 9241/72 Th b ki d i e uses a one-piece plastics braking shoeto brake a shuttle. The shoe includes a braking [52] US. Cl. 139/185,139/125 part to engage the Shuttle and guide shoes to guide the [51]Kill. (:1 D03d 49/54 Shuttle under the braking part. The Shoe caninclude [58] Field 01 Search 139/185-187, integral holding plates fsecuring the Shoe to a recip 139/183 126 rocating brake member or cancooperate with separable holding plates of metal for the same purpose.[56] References Clted UNITED STATES PATENTS 6 Claims, 7 Drawing Figures2,271,205 1/1942 Pfarrwaller 139/187 X BRAKING DEVICE FOR A SHUTTLE IN AWEAVING MACHINE This invention relates to a braking device for a shuttlein a weaving machine.

Heretofore, weaving machines which use gripper shuttles for pickingelements and in which a weft package remains outside a shed duringoperation, generally have the shuttles move through the shed at veryhigh picking speeds. As a result, rather high amounts of kinetic energymust be absorbed in bringing the shuttles to a stop after passingthrough the shed. To this end, various types of brake devices have beenused. In some instances, the brake device has been constructed with abrake part which is adapted to press against the shuttle and is mountedon a brake member. The brake member has usually been mounted toreciprocate vertically in synchronism with the weaving machine to causepressing of the brake part against the shuttle at preset times.Generally, a brake device of this type has holding plates which arescrewed onto both sides of the brake member as well as guide shoes whichare formed at the free ends of such plates to guide the shuttle. Inaddition, a plastic brake part and a rubber buffer are clamped betweenthe guide shoes and are located between the brake part and the brakemember. Also, guide ledges are provided at the front end of the guideshoe for directing the shuttle entering into the brake device.Consequently, a large number of different parts made of differentmaterials are secured to the brake member.

In operation, the parts which are secured to the brake member experiencefairly heavy wear because of friction and heating and therefore have tobe replaced at various times. If replacement is not carried out in goodtime, the shuttle ceases to be guided and centered accurately whenentering the brake device. The shuttle stop position therefore ceases tobe accurately defined, with repercussions on the accuracy of otherevents in the machine. The parts which are fitted to the brake membermust therefore be replaced in good time. Since the dismantling andadjustment of new parts entail difficulties and require expertknowledge, it sometimes occurs that parts which are not fully worn arereplaced. Therefore, the number of interruptions in operation is higherthan strictly necessary.

Accordingly, it is an object of the invention to provide a brakingdevice of relatively long life.

It is another object of the invention toprovide a braking device ofsimple construction for use in a weaving machine.

It is another object of the invention to reduce the downtime of aweaving machine due to brake replace-' ment.

It is another object of the invention to provide a braking device ofrelatively few parts.

It is another object of the invention to provide a shuttle brakingdevice which can be quickly and easily replaced in a weaving machine.

Briefly, the invention provides a braking device for braking a shuttlein a weaving machine comprising a brake member for reciprocally movingrelative to a shuttle path and a one-piece brake shoe mounted on thebrake member. The one-piece brake shoe includes a brake part or brakingsurface for pressing against the shuttle and guide shoes or jaws onopposite sides of the brake part for guiding the shuttle therebetween.

The invention thus provides fewer separate items for fitting to thebrake member than in the known devices. The braking devicecan be suchthat when worn parts are replaced, only one item, namely the brake shoe,needs to be replaced. Dismantling, and adjustment of the new brake shoe,are very simple operations.

According to a feature of the invention, the brake shoe engages aroundthe brake member by means of holding plates which are formed on and areunitary with the brake shoe and which. serve to secure the brake shoe tothe brake member. Conveniently, the holding plates have ledges whichengage in grooves in the brake member. According to :a feature of theinvention, the brake shoe is made of plastics.

More particularly, in the case of a plastics brake shoe, the volume ofresilient material can be increased considerably, giving softer guidanceand improved centering of the shuttle as well as more accuratedefinition of the shuttle stop position. The softer guidance dampsshuttle oscillations, thus reducing the risk of the picked weft yarnbeing lost because of an oscillating yarn clamp (lost yarn).

These and other objects and advantages of the invention will become moreapparent from the following detailed description and appended claimstaken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a sectional view through a conventional brake deviceof a gripper shuttle weaving machine;

FIG. 2 illustrates a view taken on line II-II of FIG.

FIG. 3 illustrates a sectional view of a braking device according to theinvention corresponding to the bottom part of FIG. 2;

FIG. 4 illustrates a side view of the braking device of FIG. 3;

FIG. 5 illustrates an alternative form of the bottom part of FIG. 3;

FIG. 6 illustrates another feature of a braking device according to theinvention; and

FIG. 7 illustrates a side view of the device of FIG. 6.

Referring to FIGS. 1 and 2, a conventional weaving machine catchingmechanism, which is covered by a cover 1, includes a guide 2 in which abrake member 3 of substantially square cross-section can reciprocatevertically. The brake member 3 has two forked ends 4 at the top, and atoggle joint 6 driven by a drive rod 5 is disposed between the ends 4.By way of two links 7,

8 the toggle joint 6 connects a stationary block 11 to the brake member3. The height of the block 11 can be adjusted by means of a screw 9.

Before each entry of shuttle 12in the catcher mechanism, the rod 5 ismoved by the machine drive into the position shown in FIG. 2, in whichthe toggle joint 6 is in an extended position, the parts which will bedescribed hereinafter and which are disposed on the bottom of the brakemember 3 are in the braking position. The rod 5 then moves to the rightas viewed in FIG. 2 causing the toggle joint 6 to bend and the brakemember and the other parts of the brake to rise so thatthe shuttle 12can go on to other operations.

Secured to the bottom of the brake member 3 by means of screws 13 andholding plates 14 are a platelike brake part 15 and a rubber pad 16above the part 15. Guide plates 17 are also clamped between the plates14 and the member 3. Those ends of the plates 17 which are on the rightin FIG. 1 from guide ledges 18 for the entering shuttle while the plates14 form guide jaws 19 at the bottom. A stationary brake plate 21 isdisposed below the shuttle.

When the shuttle 12 has entered the catching mechanism l in thedirection indicated by an arrow 22 and has been braked, the brake isreleased via rod 5. The shuttle is then moved back to the right asviewed in FIG. 1 by a drawback device (not shown) into an exactly equalposition and then conveyed by an ejector mechanism (not shown) into acurved ejection guide 23 for return to the packing mechanism and afurther passage through the shed.

Referring to FIGS. 3 and 4, the braking device of the invention has abrake member 3 which carries a onepiece brake shoe 31 made of aresilient plastics on the bottom. The brake shoe 31 comprises a brakingsurface 150 corresponding to the brake part 15, guide jaws 19acorressponding to the jaws 19, a pad 16a corresponding to the pad 16,plate-like holding or retaining parts 140 corresponding to the plates14, and ledges 18a corresponding to the ledges 18. The plate-like parts14a, i.e. holding plates engage around the bottom part of the brakemember 3 and have ledges 32 at their top ends adapted to engage ingrooves 33 in the brake member 3.

Due to the resilience of the material used for the brake shoe 31, theshoe 31 can be pushed onto the bottom end of the brake member 3 and beself-retaining. The screws 13 can be omitted or else used simply as asafeguard.

A space 34 is left between the lowest part of the brake member 3 and thepad a to enable the brake shoe 31 to be resilient. The shoe 31 is alsoformed with bores 35 for the same purpose.

The brake shoe 31 has bevelled surfaces 36 to brake the shuttle 12,shown in chain-dotted lines in FIG. 3. Consequently, the specificbraking pressure acting on the brake shoe 31 can be less than in theconstruction shown in FIGS. 1 and 2, an important consideration in thelight of the cold flow of plastics subjected to high pressures.

Referring to FIG. 5, the brake shoe 31a is formed with side recesses 37to increase the resilience of the plastics material.

Referring to FIGS. 6 and 7, the one-piece brake shoe 31b comprisesmerely the brake surface 15a, the jaws 19a and the ledges 18a. Thisbrake shoe 31b is made of plastics and is retained by means of topledges or the like 41 in metal holding plates 14a which fit intoappropriate grooves 42 in the shoe 31b. Also, the brake shoe 31b isformed with grooves 43 in which projections 44 on the plates 14a engage,to prevent the brake shoe 31b from shifting to the left as viewed inFIG. 7 as a result of the braking action on the shuttle.

What is claimed is: 1. A braking device for braking a shuttle in aweaving machine comprising a brake member for reciprocally movingrelative to a shuttle path; and

a one-piece brake shoe mounted on said brake member, said brake shoeincluding a braking surface for pressing against a shuttle and guidejaws disposed on opposite sides of said braking surface for guiding ashuttle therebetween.

2. A braking device as set forth in claim 1 wherein said brake shoefurther includes a pair of integral holding plates disposed on oppositesides of said brake member and securing said brake shoe to said brakemember.

3. A braking device as set forth in claim 2 wherein each holding platehas at least one ledge and said brake member has a plurality of grooves,each groove receiving a respective ledge.

4. A braking device as set forth in claim 3 wherein said brake shoe ismade of plastics.

5. A braking device as set forth in claim 4 wherein said holding platesresiliently engage said brake member thereon.

6. A braking means as set forth in claim 1 wherein said brake shoe ismade of plastics.

1. A braking device for braking a shuttle in a weaving machinecomprising a brake member for reciprocally moving relative to a shuttlepath; and a one-piece brake shoe mounted on said brake member, saidbrake shoe including a braking surface for pressing against a shuttleand guide jaws disposed on opposite sides of said braking surface forguiding a shuttle therebetween.
 2. A braking device as set forth inclaim 1 wherein said brake shoe further includes a pair of integralholding plates disposed on opposite sides of said brake member andsecuring said brake shoe to said brake member.
 3. A braking device asset forth in claim 2 wherein each holding plate has at least one ledgeand said brake member has a plurality of grooves, each groove receivinga respective ledge.
 4. A braking device as set forth in claim 3 whereinsaid brake shoe is made of plastics.
 5. A braking device as set forth inclaim 4 wherein said holding plates resiliently engage said brake memberthereon.
 6. A braking means as set forth in claim 1 wherein said brakeshoe is made of plastics.